1. Field of the Invention
This invention relates to fiber optic image transmitting devices and more particularly to means for enhancing the resolution of optical images transmitted thereby.
2. Description of the Prior Art
Bundles of optical fibers having their corresponding opposite ends arranged in identical geometrical patterns afford image transmitters which conduct image forming light by the well known principles of total internal reflection. The packing tightness and particular mosaic patterning of the fiber ends, their respective diameters and cladding thicknesses as well as absence or existence of broken or otherwise damaged fiber cores individually and collectively affect the image resolving power of the bundles whether they are of the rigid or intermediately flexible (fiberscope) type.
In view of the fact that spacing between light-conducting cores resulting from fiber claddings, defects of fiber breakage and/or blemishing and foreign matter inclusions or the like are at least to some extent inevitable, dynamic image enhancement schemes have been devised to integrate the mosaic patterning of fiber ends and non-conducting or partially conducting spaces resulting from fiber breakage or transmission variations between fibers.
The theory of dynamic scanning is explained in the Journal of the Optical Society of America, Vol. 47, No. 5, May, 1957, pages 423-427 and also in the New York Academic Press, 1967.
The ungainliness, complexity and costliness of these earlier applications of dynamic scanning have largely outweighed and/or defeated their advantages. U.S. Pat. No. 3,016,785 is exemplary. Its complex and ungainly mechanism for effecting a break-up motion between opposite ends of a fiber bundle and optical images received and emitted thereby is not utilitarian in fiber optic endoscopes which must not be so distally or otherwise encumbered.
Similarly, U.S. Pat. Nos. 3,217,588 and 3,217,589 synchronously nutate images at the receiving and output ends of fiber optic cables using motor driven geared mechanisms which are bulky and heavy, complex and costly and limited to use in areas other than those of endoscopy where unencumbered instrumentation is required.
In application Ser. No. 853,060 filed on Nov. 21, 1977 there is disclosed an image enhancement system for fiberscopes which overcomes many of the problems and/or drawbacks of the aforesaid older dynamic image enhancement schemes but which is somewhat less than optimally applicable to fiberscopes having severe limitations of equipment space as do the smaller varieties of medical endoscopes, for example.
Although it may be possible to reduce the size of the configuration of the Ser. No. 853,060 apparatus to the very small space permitted in a medical endoscope, i.e. a fiberscope having a short-focus objective lens system, other factors such as width of field of view become limited.
Accordingly, it is a principal object of this invention to provide an improved dynamic image enhancement system which has special applicability and adaptability to the small space requirements of medical endoscopes, but without limitation to such scopes.
Another object is to accomplish the foregoing without encumbrance of the endoscopes and in a simple, highly effective and inexpensive manner.
Other objects and advantages of the invention will become apparent from the following description.